The present invention relates to imaging, and, more particularly, to a system and method for determining presence, absence and/or location of a thermally distinguishable tissue region in a living body.
A viewer of a two-dimensional image perceives a structure such as depth, thickness or the like, when the two-eyes of the viewer see slightly different images of a three-dimensional scene. The brain of the viewer transforms the different images viewed by the left eye and right eye into information relating to the third dimension of the image, and the image appears to be “three-dimensional”. A technique in which such structures are visually understood is known as stereoscopy.
In a conventional imaging apparatus, a visible stereoscopic image is formed using a left camera which images the scene from the left of the scene, a right camera which images the scene from the right of the scene, and a three-dimensional image synthesis device which synthesizes images obtained by the left and right cameras.
In medical applications, oftentimes an infrared camera is employed, for example, for diagnosing a thermally distinguishable site a human body or for other purposes. Infrared cameras produce a two-dimensional image known as a thermographic image. The thermographic image is typically obtained by receiving from the body of the subject radiation at any one of several infrared wavelength ranges, and analyzing the radiation to provide a two-dimensional temperature map of the surface. The thermographic image can be in the form of either or both of a visual image and corresponding temperature data. The output from infrared cameras used for infrared thermography typically provides an image comprising a plurality of pixel data points, each pixel providing temperature information which is visually displayed, using a color code or grayscale code. The temperature information can be further processed by computer software to generate for example, mean temperature for the image, or a discrete area of the image, by averaging temperature data associated with all the pixels or a sub-collection thereof.
Based on the thermographic image, a physician diagnoses the site, and determines, for example, whether or not the site includes an inflammation. It is recognized that the use of an infrared camera has a problem in that the obtained image is not as realistic as an actual visual observation, and thus sufficient information required for diagnosis is not obtained. Accordingly, the diagnosis of a subtle inflammation symptom relies heavily on the experience and intuition of the physician.
A technique attempting to resolve the above drawback is disclosed in U.S. Pat. No. 7,072,504. In this technique, two infrared cameras (left and right) are used in combination with two visible light cameras (left and right). The infrared cameras are used to provide a three-dimensional thermographic image and the visible light cameras are used to provide a three-dimensional visible light image. The three-dimensional thermographic and three-dimensional visible light images are displayed to the user in an overlapping manner.
Also of interest is U.S. Pat. No. 6,442,419 disclosing a scanning system including an infrared detecting mechanism which performs a 360° data extraction from an object, and a signal decoding mechanism, which receives electrical signal from the infrared detecting mechanism and integrates the signal into data of a three-dimensional profile curved surface and a corresponding temperature distribution of the object.
The above solutions, however, are far from being satisfactory, particularly in the field of medical imaging, because they fail to provide sufficient resolution for the physician to accurately determine the location of a thermally distinguishable tissue region in the body of the subject.
The present invention provides solutions to the problems associated with prior art thermographic imaging techniques.